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the sum of the digits of a 2-digits number is 8.if the number obtained by Interchanging the digits is 36 more than the original numbers. find the numbers. |
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Answer» ong>Answer:
This IMPLIES that x2+2ax=4x−4a−13 or x2+2ax−4x+4a+13=0 or x2+(2a−4)x+(4a+13)=0 Since the equation has just ONE SOLUTION instead of the USUAL two distinct solutions, then the two solutions must be same i.e. discriminant = 0. Hence we get that (2a−4)2=4⋅1⋅(4a+13) or 4a2−16a+16=16a+52 or 4a2−32a−36=0 or a2−8a−9=0 or (a−9)(a+1)=0 So the values of a are −1 and 9.
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